When building your own computer one part was always a mystery to me: the motherboard. Picking a CPU/GPU/memory is easy- you just figure out where the various chips are in the low end to high end scale, do a little market research on what current games demand, and pick the parts from their respective continuums of low-to-high-end models.

A mother board is more complicated though. Its features are not as obvious as "this motherboard is faster than that motherboard". Now you need to deal with part compatibilities, bus speeds, maybe power management stuff, etc.

I'm interested in a short guide for selecting a motherboard, especially- what pitfalls to avoid (for example, can bus speed become a bottleneck?).

To clarify: I'm not looking for motherboard recommendations. I'm looking for guidance regarding how to evaluate the fitness of a motherboard given the rest of the computer parts.

Price vs. Upgradability vs. Expandability. Do you intend to fill the mobo with as much Ram as it can use, or do you intend to upgrade the amount over time? Are the number and type of expansion slots suitable to your needs, or will you need more in the future? I've got a system with an Asus board that cost me $25 at the time (Am2+) and it does everything I could ask of it and more... and I don't need more than the 2 expansion slots or the 2 ram slots. For what I needed, it's perfect. The Short Guide? Determine what you need, and find boards that fit those needs.
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Bon GartNov 13 '12 at 22:44

Those things are uniform for any computer - that is the mobo must be capable of running the internal devices on their maximum speed.

If you are planning to upgrade the computer in the future, then you need to consider cashing out for a more expensive alternative that support faster RAM and CPU than you can currently afford. It is also unwise to get a mATX mobo with 2 or less PCIe slots in that case.

Step 2 may require special attention depending on the manufacturer of the motherboard. I don't see why people are afraid of naming brands. Intel, for instance will not always support "custom" speed RAM because their server and workstation boards aim at stability. This varies. Check the documentation of potential motherboards.

An interesting question. Not quite one matching the most asked questions on this site, and a bit to broad to give a clear precise answer.

Personally I select my motherboards as follows:

Select how much you want to spent, based on that make a rough idea on which CPU, which graphical card, how much memory etc. etc.

Consider which items you want to keep from your old PC. (e.g. old network cards, high quality audio, RAID cards, SSDs, etc. etc.)

Based on the preferred CPU select which chipset you want. Sometime this is easy (e.g. for a nehalem i7 there was only one chipset: X58), sometimes you have the luxury to choose between a few.

All of this leaves you with a few ideas on paper, but no concrete motherboard. Not yet anyway.

Next I select which brand. Without naming specific companies there are significant differences between brands.

Some concentrate on rock stable systems and workstation features.

Some seem to concentrate on speed and overclocking.

Some are plain cheap. Most of those work, but if you still want a BIOS update in 3 years time you might just be out of luck.

I have specific names which I can assign to all three of these, but S.U. is not the place the name them. Some research should quickly identify them though.

You should be down to a dozen boards by now.

Look at the boards features and sort them by what else is important to you. E.g:
- Can you add more memory later? (4 or 6 sockets for DIMMs?)
- How many expansion slots. (currently PCIe slots). Many people have enough with one x8 or 16 slot. Sometimes you want more for other cards and or dual GPU setups.
- Do you want a specific feature? E.g. Firewire to connect to professional audio equipment? eSATA for rapid connection to an external (backup) drive. A Thunderbolt interface? A PS/2 connector for that comfortable keyboard you already had? etc. etc.

Usually you end up with only a few choices. Add price and availability and the choice is usually not a hard one.

In general the first question to ask:
Are there any devices you currently have that you want to continue to use or reuse?
e.g. If you've got an old IDE DVD drive and don't want to buy a new one, you've immediately eliminated a vast chunk of the current motherboards.

Then you determine the CPU socket type you need, currently if its an Intel CPU then LGA1155, or if its AMD AM3+.

Next you pick what is typically termed the 'chipset', basically the core feature set of the motherboard. Intel for example have 3 core chipsets for their LGA1155 socket. Z, H, and Q. Each of these is aimed a slightly differing target market. Z for example is the only one that allows for overclocking. This isn't 'exact' as the mobo can add additional features using other chips...but its a good start.

Finally size, mini/micro-ITX, ATX etc. If you've picked your case already then you might have already limited yourself. If you've got a standard ATX case, then you've got the most options. Remember bigger doesn't always mean better. The bigger board might have more sockets for hard drives and cards, but it also draws more power, and all those extra features means it probably takes longer to boot too. For a typical PC today, a microATX or mini-ITX is enough.

Once you've picked your chipset and size, its basically then down to budget. All the motherboard manufactures will typically have 4-6 products for each chipset/size, going from barebones basic features to additional nice-to-haves (like WiFi, mSATA, voltage monitoring points).

I would say manufacturer is less important than it was, and most boards will perform acceptably for the majority of people. And remember that people will post negatives of a product, but don't bother if its just works!

It depends on what you want to do with your PC. Shall it be fast for games? Shall it only be "good" enough for work?

In whatever case, you should direct your choices to what you want, e.g. if you want to play Battlefield 3 on highest settings, you'll need a good RAM, a high-end GC and a high-end CPU. Now, if you found the RAM, GC and CPU you can adapt the motherboard to it.

But, that's not all, as my predecessors already said, there are some brands that are more compatible with each other than others.
Also, you should look for what interfaces you want to have on your mainboard. (e.g. SATA6GB,USB3) etc.

And if you still do not know, what mainboard to take, you can read the specs of the high-end PCs (lets say from AlienWare etc.) and look what mainboards they build into their PCs.